How exactly can a stalker track me online if I simply stop logging in to services? Honest question, because I don't know why Tor would be any better than simply browsing in incognito mode
IP addresd is the big one, but there are other things that let you narrow down users on the same IP or a user switching between IPs, like tracking cookies, identification of which subset of hardware your GPU falls into based on how it renders some WebGL stuff (which can sometimes allow identification of a specific model of phone, especially when combined with other fingerprinting methods), specifics of screen size, what plugins/extensions you have installed at specific version numbers, etc. Tor only directly addresses the IP point, but the Tor browser should be disabling that other leaky browser stuff as well. I think they were accidentally leaking IPs through WebRTC a while back, or something like that, and I'm sure there will be more issues going forward.
You still are sending packets over your router, to your ISP, out into the internet, and to the destination server. You leave fingerprints everywhere (browser, os, resolution, fonts, enabled features, cookies, etc.) Forever cookies, DNS cookies. The list goes on.
You are being tracked at the very least as an abstract person. If any of the above fingerprints are linked to a real identity (logging in just once even, or posting your email on a forum) then you are now being tracked even logged out.
If you use Tor and log into services it has no benefits. Tor, the browser and other distributions, will still leave fingerprints but they will no longer be unique and match only you but everyone using tor.
Tor, the protocol, will hide that you are the one receiving or sending packets.
"why Tor would be any better than simply browsing in incognito mode"
Incognito mode does nothing to hide packets or source/destination you are communicating to. Your ISP could literally pull up all non-https sites you visited along with their content, assignable to you, airstrike, as a person. Tor would block this.
